City of Stars by Mary Hoffman
Tomboy Georgia is being bullied by her foster brother. When she purchases a wooden figure of a winged horse, it takes her to Talia, a parallel world resembling Italy. There, she meets a young boy named Cesare who works in the stables and is helping his father prepare for the big horse race coming up. A winged horse is born in Cesare's stable, something that happens only once in a hundred years. It is believed to bring good luck to the city in which it is born. Could it help Cesare's city win the race that is so important?
With enemies lurking nearby, keeping this a secret might be difficult. The di Chimici will do anything to stop their rivals from winning. And why was Georgia brought to Talia? She knows there must be a reason, but what?
Dreaming of a city with flying horses was one thing . . . But coming face to face with someone she knew to be dead - that was something else again.
Previous book: City of Masks
Next book: City of Flowers.